Friday 24 February 2006 19.05 EST
First published on Friday 24 February 2006 19.05 EST

At least eight prominent Chinese human rights activists have vanished after they joined one of the first overt attempts to coordinate a nationwide protest against the authorities since the 1989 democracy demonstrations.

Political security police are thought to have detained the campaigners, who disappeared soon after they joined a relay hunger strike that has reportedly attracted several dozen participants in 16 provinces.

No official explanation has been given. The government's propaganda department has forbidden the domestic media from reporting anything to do with the campaign, which was launched by a Beijing lawyer, Gao Zhisheng, on February 4 in protest against police brutality. Mr Gao said at least a dozen participants had been detained, although some were released on condition that they drop their involvement. Many are veteran rights campaigners, who have been held in the past.

Among those still missing is Hu Jia, who played a leading role in exposing the contaminated blood scandal that infected tens - and possibly hundreds - of thousands of people with HIV in Henan province. Mr Hu was one of the first to join the relay, staging a 24-hour hunger strike.

He was last seen on February 16 by associates who said he was followed by plain-clothes police. His wife said she had filed a missing person's report. But police have given her no information about her husband's condition or whereabouts.

A similar fate has befallen Qi Zhiyong, a pro-democracy activist whose legs were amputated after he was shot during the 1989 protests. He disappeared on February 15.

The press freedom group, Reporters Without Borders, said another hunger striker, Yu Zhijian - a former teacher who threw paint on a vast portrait of Mao Zedong in central Beijing during the 1989 demonstrations, has been charged with subversion. His detention came in the same week that his friend and fellow portrait defacer, Yu Dongyue, was released after almost 17 years in prison. Solitary confinement and other forms of psychological torture had taken such a toll that he was unable to recognise his mother.

Human rights groups fear that those arrested in the past fortnight could also be subjected to torture and ill-treatment. "The irregular nature of their detention makes it even more difficult than normal to monitor their situation, and the authorities take no responsibility for the disappearances," said the China-based group, Civil Rights Defenders. "Law enforcement officials and local authorities who violate the law by subjecting these people to arbitrary detention or torture must be investigated and prosecuted."

The authorities have been struggling to control a wave of unrest. The Ministry of Public Security reported 87,000 protests, riots or other "mass incidents" last year, up 6.6% from 2004. Almost all protests have been confined to specific local issues - usually disputes over land - but security officials fear that malcontents are becoming more organised.

Lawyers, academics and local activists are increasingly roaming the country, coordinating demonstrations and educating farmers about their legal rights.

Until now there has been no nationwide campaign. But this month the dissident lawyer, Mr Gao, began one by organising a hunger strike to protest against beatings by police and thugs of rights activists in Guangdong and Shandong provinces.

Security officials appear to be taking no chances that the hunger strike might spread. Detainees can be held for a few days informally - often in cheap hotels - or kept in jail if there is a possibility that they will be charged with subversion or endangering national security.